Medical instrument and method for endoscopic removal of the saphenous vein

ABSTRACT

A medical instrument for endoscopic removal of the saphenous vein has an elongated shaft which hat at the distal end a spatula tip and in whose proximal region is arranged a laterally projecting handle. The instrument further has an endoscopic optical system which has an eyepiece cup that is arranged at the proximal end of the instrument. The handle is joined to the shaft in such a way that an outer side of the instrument facing away from the handle continuously has a surface that, from the distal to the proximal end, is free of projections. The eyepiece cup is arranged in oblique orientation with respect to a longitudinal center axis of the shaft and encloses with the handle, with respect to the longitudinal center axis, an angle of less than 90°.

RELATED APPLICATIONS

This is a continuation-in-part of currently pending U.S. patentapplication Ser. No. 09/504,777, filed Feb. 11, 2000, now U.S. Pat. No.6,413,208 which is a continuation of pending PCT Application Serial No.PCT/EP99/04185, filed Jun. 17, 1999, which claims the benefit of DE 19827 360.6, filed Jun. 19, 1998, the contents of each of which areincorporated herein in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a medical instrument for endoscopicremoval of the saphenous vein, having an elongated shaft which has atthe distal end a spatula tip and in whose proximal region is arrange alaterally projecting handle; and further having an endoscopic opticalsystem which has an eyepiece cup that is arranged at the proximal end ofthe instrument.

The present invention further relates to a method for endoscopic removalof the saphenous vein.

An instrument of the aforesaid kind is known from the company document“Endo World,” CHIR No. 4-D, 1997, published by Karl Storz GmbH & Co.,Tuttlingen, Germany. An instrument of this kind is illustrated on page 3of this document under the designation “optical retractor.”

The saphenous vein (vena saphena magna) is a long leg vein that runs onthe medial (i.e. inner) side of the leg from the inside of the anklealong the lower leg and thigh to the groin.

The saphenous vein is often removed for use as a transplant in cardiacand vascular surgery. In conventional surgical methods for removal ofthe great saphenous vein, either a single long incision is made alongthe inner side of the leg, or several short incisions, separated fromone another, are made. Using instruments (called “vein dissectors”)introduced through these incisions, the saphenous vein is detached fromthe surrounding connective tissue and its lateral branching vessels. Thedetached and isolated vein is then removed through a single longincision or several separate incisions entails the risk, however, ofinjury to the medial lymph bundle and thus infection of the operativearea.

The article “Minimally invasive, video-assisted vein harvesting forcardiac and vascular surgical procedures” by Lutz et al. (1997), inEuropean Journal of Cardio-Thoracic Surgery 12, pp. 519-521, describesan alternative method for removing the saphenous vein, in which the veinis removed using minimally invasive techniques under endoscopicobservation. For this purpose, only a single small (2-3 cm long)incision is introduced in the vicinity of the knee joint. Through thisincision, the instrument cited initially is introduced upward along thethigh portion of the vein into the groin, and downward along thelower-leg portion of the vein to the inner ankle. The vein is therebydetached from consecutive tissue and lateral branching vessels, and theentire vein is pulled out through the single incision in the kneeregion. This endoscopic removal technique is gentle on the tissues, ascompared to the earlier removal method described above, because only theone incision is required, and the patient's postoperative discomfort andthe risk of surgical infection are much lower. In addition, removalusing this newer method always takes place under endoscopic visualsupervision.

The instrument known from the aforementioned German company document“Endo World,” which is suitable for the procedure described above, hasan elongated shaft that carries at it proximal end a laterallyprojecting handle and an eyepiece cup belonging to an endoscopic opticalsystem. The shaft is configured from the proximal to the distal end—atwhich a narrow spatula tip, tapering in the distal direction andslightly curved, is configured—as an approximately kidney-shaped troughfor external reception of an optical shaft of the endoscopic opticalsystem, i.e. the endoscope shaft rests on the outside of the shaft inthe trough. The endoscopic optical system, made up of the optical shaftand eyepiece with eyepiece cup, can be removed from the shaft by pullingthe endoscopic optical system in the proximal direction off the shaft,through an attachment segment of the handle. The shaft of the medicalinstrument is approximately 30 cm long in order to be able to reach theends of the vein from the single incision in the knee region.

With the known instrument, the handle is attached to the shaft in such away that the shaft is widened in the region of the handle, i.e. theouter side of the instrument, facing away from the handle, has a step inthe region of the handle extension. In addition, the eyepiece cup isarranged at the proximal end of the shaft in such a way that thelongitudinal center axis of the eyepiece cup runs as a straight-linecoaxial extension of the longitudinal center axis of the instrumentshaft, so that the eyepiece cup extends circumferentially beyond theshaft on all sides.

This configuration of the known instrument is, however, disadvantageousin the context of a surgical procedure for removing the great saphenousvein.

This is because in the endoscopic procedure for removal of the greatsaphenous vein, the instrument is introduced through the incision in theknee region and is pushed upward along the vein to the groin, anddownward into the ankle region.

In order to allow the entire vein to be removed through a singleincision, the entire length of the medical instrument must be utilized,since the instrument must be advanced from the knee to the groin anddown to the ankle along the vein. Since the vein runs just beneath theskin, the shaft of the instrument must be advanced almost parallel tothe skin surface, so that the segment of the shaft located outside theincision as the shaft is advanced along the vein must be pushed forwardwhile being held closely as possible against the leg.

With the known instrument, the fact that the attachment segment of thehandle and the eyepiece, as described above, project laterally in theproximal region of the shaft that remains outside the body means thatthe instrument is considerably widened in its proximal region above theshaft on the outer side of the instrument that rests against the leg.This widening, however, prevents the instrument from lying close to thepatient's leg, with the consequence that the spatula tip cannot be slidforward along the vein just beneath the skin surface. Such is the case,at least, when the instrument has already been advanced a long way intothe operative area. Because of the widening of the instrument in theproximal region on the outer side facing away from the handle, it isthus almost impossible to guide the spatula tip deep into the operativearea along the saphenous vein while still parallel to the skin surface.Instead, the spatula tip penetrates into deeper tissue and can therebyresult in undesirable damage to uninvolved tissue. To eliminate thisrisk, the known instrument can be used only up to a certain insertiondepth of the shaft into the operative area. A further disadvantage ofthe known instrument furthermore consists in the fact that withincreasing insertion depth of the shaft into the incision, the cameraconnected to the eyepiece for observation of the operation through theendoscopic optical system is, beyond a certain insertion depth, in suchclose contact against the patient's leg that the camera, whose housingdimension transverse to the shaft axis is wider than the shaft itself,prevents parallel subcutaneous advancement of the instrument. The camerafurthermore prevents the introduction of further auxiliary instrumentsinto the incision. Handling of the known instrument is thus also mademore difficult.

U.S. Pat. No. 5,667,480 also discloses an instrument and method forendoscopic removal of the saphenous vein in which the aforesaiddisadvantages also exist, namely that the shaft is widened in the regionof the handle attachment, and that the eyepiece is axially aligned.

U.S. Pat. No. 5,373,840 discloses a comparable instrument, having ahandle protruding laterally from the shaft and having an integratedendoscopic optical system that transfers the observed image directly toa monitor. An eyepiece can also be provided in conventional fashioninstead of the monitor, but there is no indication as to how theeyepiece would then be arranged.

Against this background, it is the object of the present invention tomake available a medical instrument of the aforesaid kind which makes itpossible to remove the great saphenous vein through the smallestpossible incision in the patient's body, the spatula tip of theinstrument is to be insertable into the incision and along the vein justbeneath the skin surface over as much as possible of the entireinsertion depth of the shaft.

SUMMARY OF THE INVENTION

This object is achieved, in terms of the medical instrument citedinitially, in that the handle is joined to the shaft in such a way thatan outer side of the instrument facing away from the handle has acontinuous straight surface that, from the distal to the proximal end,is substantially free of projections, and that the shaft-handle plane isinclined with respect to the shaft-eyepiece cup plane at an angle ofless than 90°.

As a result of the design according to the present invention, themedical instrument receives on its outer side facing away from thehandle a uniform surface, running from the proximal end to the beginningof the distal spatula tip, that is free of projections and therebyallows the proximal region of the instrument to lie in close contactagainst the outer surface of the patient's leg, and thus readily permitsthe shaft of the spatula tip to be slid along the vein just beneath theskin surface. Because the eyepiece cup is arranged, according to thepresent invention, in laterally oblique fashion, it also no longerextends beyond the outer side of the instrument facing away from thehandle.

The design according to the present invention, having an outer side thatis free of projections, makes it possible to introduce the medicalinstrument into the patient's leg over the entire length of its shaft.Since there are no enlargements, ridges, or the like in the proximalregion of the instrument, the instrument can be introduced in closelycontacting fashion in the region of the incision and held in thatfashion during the operation. The instrument according to the presentinvention thus makes it possible, even with a small incision, to utilizethe entire length of the shaft.

This uniform surface also allows easy insertion of further auxiliaryinstruments, for example vein dissectors, dissecting or graspingforceps, scissors, ligature loops, or the like, without requiring alarger incision.

The aforesaid outer side of the medical instrument according to thepresent invention need not be continuously integral. It can beconstituted from multiple surfaces, arranged one behind another, whichbelong to different constituents of the instrument (such as theendoscope, handle, and shaft that optionally are detachable from oneanother. What is critical in this context is that the aforesaid outerside is free of projections that protrude distinctly beyond the outerperiphery of the shaft. The medical instrument is thus of substantiallyflat configuration on the side resting against the patient's leg, andthe instrument is slid into the incision along the patient's leg on thatouter side.

A further advantage of the instrument according to the present inventionis the fact that the physician can always bring his or her eye to theeyepiece cup in unimpeded fashion regardless of the insertion depth ofthe instrument, since the eyepiece cup stands out from the shaft andthus from the patient's leg. In the event a camera is used on theinstrument eyepiece, introduction of the auxiliary instruments isadvantageously no longer impeded by the attached camera. As anadditional result, handling of the instrument according to the presentinvention is advantageously improved.

The method of the present invention includes the step of providing aninstrument according to the present invention.

In a preferred embodiment, the handle has an attachment segment that isconfigured in the upper region in the form of a sleeve which fits overan axial portion of the shaft with the least possible material thicknesson the outer side of the shaft facing away from the handle.

This feature has the advantage on the one hand of bringing about astable join between the handle and the shaft, and on the other hand ofkeeping the outer side of the instrument, facing away from the handle,free of shoulders, steps, or protrusions.

In a further preferred embodiment, a longitudinal center axis of theeyepiece cup forms an angle in the range from 30° to 60°, preferably45°, with the longitudinal center axis of the shaft.

If the eyepiece cup is arranged to protrude at an angle within thisrange, it is particularly convenient for the physician to look into theeyepiece cup from the side of the instrument facing away from thepatient's body.

In a further preferred embodiment, the eyepiece cup is arranged on aneyepiece housing of the endoscopic optical system which has an outerside, facing away from the eyepiece cup, that approximately aligns withthe outer side of the shaft facing away from the handle.

The advantage of this feature is that the aforesaid outer side of theeyepiece housing constitutes a shoulder-free prolongation of the outerside of the instrument facing away from the handle, thus improvingguidance of the instrument along the leg by way of the extended contactsurface constituted by the eye-piece housing.

In a further preferred embodiment, the shaft is configured as acircumferentially closed hollow shaft for reception of an optical shaft,extending to the spatula tip, of the endoscopic optical system.

The advantage of this feature is that the optical shaft of theendoscopic optical system received in the shaft experiences improvedguidance upon insertion along the shaft and improved retention in theshaft, thus facilitating installation of the endoscopic optical systemon the instrument shaft. A closed shaft having an internally locatedoptical shaft moreover has the advantage that the outer surface of theshaft can be configured to be smooth and have no sharp edges all around,thus allowing the shaft to be more easily advanced in the operativearea. The optical shaft is moreover protected from contamination. Inaddition, further auxiliary instruments can be introduced into theinstrument shaft in order to remove connecting tissue and detach thevein. All these auxiliary instruments can then be enclosed by the shaftand thus also protected from contamination. Above all, the instrumentsexperience “non-jerky” guidance along the shaft toward the distal end.

In a further preferred embodiment, the outer side of the shaft facingaway from the handle is flat in cross section, viewed toward thelongitudinal center axis of the shaft, with a slight concave curvature.

Since the outer side of the shaft facing away from the handle is guidedalong the outer surface of the leg upon insertion of the instrument, theadvantage of this feature is that this outer side rests in planarcontact against the leg and thus al-lows improved guidance of the shaftalong the leg. The slightly concave configuration additionally has theadvantage that the segment of the shaft already introduced into theincision experiences, with the curvature, a certain positive guidancealong the vein.

In a further preferred embodiment, an outer side of the shaft facingtoward the handle is convexly curved in cross section when viewed towardthe longitudinal center axis of the shaft.

The advantage of this feature is that the optical shaft received in theshaft automatically assumes a centered position in the instrument shaftin the curvature upon insertion into the shaft, thus furtherfacilitating installation of the endoscopic optical system on the shaft.

In a further preferred embodiment, the spatula tip has a spoon-shapedcurvature that opens toward the side of the instrument facing away fromthe handle.

The advantage here is that as the instrument is slid forward, anoperative cavity, which can be easily illuminated and observed throughthe endoscopic optical system, is formed in the region of the distalspatula tip. The spoon-shaped curvature of the spatula tip also protectsthe region in which the distal elements of the auxiliary instruments,for example mouth parts of forceps of the like, are actuated.

In a further preferred embodiment, the spatula tip has a lateralwidening so that it extends beyond the shaft, at least on one side,transversely to its longitudinal center axis.

The advantage of this feature is that the operative cavity created bythe spatula tip as the shaft is advanced is enlarged as compared to theoperative cavity created by the spatula tip of the known instrument. Anenlarged operative cavity has the advantage that more space is createdfor the mouth parts of the auxiliary instruments.

In a further preferred embodiment, the spatula tip tapers toward thedistal end.

The advantage of this tapering is that it facilitates advancement of theinstrument according to the present invention through the bodily tissue.

In a further preferred embodiment, the handle projects from the shaftobliquely toward the distal end of the shaft.

The advantage of this feature is that the instrument can be introducedinto the incision, at the handle which is thus inclined in the insertiondirection, with a straight hand position and thus forcefully, thusfurther improving handling of the instrument according to the presentinvention.

The longitudinal center axis of the handle and the longitudinal centeraxis of the shaft define a first plane and the longitudinal center axisof the eyepiece cup and the longitudinal center axis of the shaft definea second plane. The first plane is inclined with respect to the secondplane at an angle of less than 90°, which, looking down the length ofthe shaft from its proximal to its distal end, may be in either aclockwise or a counter-clockwise direction.

Often, though not always, it will be more advantageous to have the firstplane inclined with respect to the second plane at an angle of 0°. Theadvantage of this angle is that the handle and the eyepiece cup protrudefrom the shaft in a single plane, thus achieving the advantage thatafter introduction of the instrument, it can also be rotated about itslongitudinal axis without thereby encountering the eyepiece cup as anobstacle. Rotation of the instrument as it is advanced may be used, forexample to deflect side branches of the saphenous vein as the instrumentis advanced.

The degree and direction of the angle that would be most advantageous,however, may depend upon various factors, such as whether the physicianis right-handed or left-handed, into which leg the instrument is beinginserted, the physician's operating style, or a preference with respectto achieving maximization of both viewing and rotational capability.Often, though not always, this angle will be less than 10°.

Further advantages are evident from the description below and from theappended drawings.

It is understood that the features mentioned above and those yet to beexplained below can be used not only in the respective combinationsindicated, but also in other combinations or in isolation, withoutleaving the context of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view of a medical instrument according to thepresent invention, partially in a longitudinal section.

FIG. 2 shows a section through the instrument along line II—II in FIG.1, at enlarged scale.

FIG. 3 shows a plan view of the endoscopic optical system received bythe instrument in FIG. 1.

FIG. 4 shows a schematic presentation to explain the method for removingthe saphenous vein from a leg.

FIG. 5 shows a plan view of the distal end of a vein dissector that isused to remove the great saphenous vein.

FIG. 6 shows a front view of the distal end of a vein dissector that isused to remove the great saphenous vein.

FIG. 7 is a schematic representation of the aforementioned first planeinclined with respect to the aforementioned second plane in a clockwisedirection when looking down the length of the shaft from its proximal toits distal end.

FIG. 8 is a schematic representation of the aforementioned first planeinclined with respect to the aforementioned second plane in acounter-clockwise direction when looking down the length of the shaftfrom its proximal to its distal end.

DETAILED DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 depict a medical instrument, labeled with the generalreference character 10, for removing the saphenous vein (vena saphenamagna).

Medical instrument 10 has an elongated shaft 12 which carries at itsdistal end a spatula tip 14 and in whose proximal region is arranged ahandle 16 that protrudes laterally from shaft 12.

Shaft 12 has an outer side 18 facing away from handle 16. Outer side 18is that side which, upon introduction of shaft 12 into the leg of apatient, rests against the outside of the leg with its region locatedoutside the incision, and whose already-inserted region is guided alongthe vein.

As is evident from FIG. 2 outer side 18 is of substantially flatconfiguration in cross section, viewed toward a longitudinal center axis20 of shaft 10, with a slight concave curvature.

Instrument 10 furthermore has an endoscopic optical system 22, removablefrom shaft 12 and from handle 16, that is shown in FIG. 3 in isolation,removed from shaft 12.

Endoscopic optical system 22 has at the proximal end an eyepiece housing24 having an eyepiece cup 26. Adjoining eyepiece housing 24 distally isan optical shaft 28. Optical shaft 28 is configured as a cylindricaltube in which an optically imaging system, comprising a lens system,aperture stops, filters, etc. or a coherent optical fiber bundle, isarranged. Also arranged in optical shaft 28 is a light-delivering fiberbundle with which light is delivered into the operative area. Providedfor that purpose on eyepiece housing 24 is a connector 30 for attachinga fiber optic cable (not shown) that can be connected to a light source(not shown).

When endoscopic optical system 22 is mounted on shaft 12, eyepiece cup26 is arranged on the same side as handle 16, directed obliquely, withrespect to longitudinal center axis 20 of shaft 12, toward the proximalend.

In this context, a longitudinal center axis 32 of eyepiece cup 26 formsan angle in the range from 30° to 60°—in FIG. 1 an angle ofapproximately 45°—with longitudinal center axis 20 of shaft 12.

Referring to FIGS. 7 and 8, the longitudinal center axis 48 of thehandle 16 and the longitudinal center axis 20 of the shaft 12 define afirst plane 100, and the longitudinal center axis 32 of the eyepiece cup26 and the longitudinal center axis 20 of the shaft 12 define a secondplane 102. The first plane 100 is inclined with respect to the secondplane 102 at an angle 104 of less than 90°, which, looking down thelength of the shaft from its proximal to its distal end, may be ineither a clockwise (FIG. 7) or a counter-clockwise (FIG. 8) direction.

The degree and direction of the angle 104 that would be mostadvantageous, however, may depend upon various factors, such as whetherthe physician is right-handed or left-handed, into which leg theinstrument is being inserted, the physician's operating style, or apreference with respect to achieving maximization of both viewing androtational capability. Often, though not always, the angle 104 will beless than 10°.

Connector 30 for attaching the fiber optic cable protrudes approximatelyat right angles from instrument 10 on the same side as handle 16 andeyepiece cup 26.

Handle 16 comprises an attachment segment 34 that runs approximately atright angles to shaft 12, and an actual handle segment 36 that hasfinger recesses 38.

Handle 16 is joined to shaft 12 in such a way that outer side 18 ofshaft 12 facing away from handle 16 forms, in the region of attachmentsegment 34 of handle 16 and with an outer side 40 of attachment segment34, a substantially uniform surface that is substantially free ofprojections or shoulders.

Eyepiece housing 24 similarly has a corresponding outer side 42 thatproximally adjoins outer side 40 of attachment segment 34 of handle 16and thus approximately aligns with outer side 18 of the shaft.

The entire outer side of instrument 10, composed of outer sides 18, 40,42, thus has a uniform surface from the distal to the proximal end, i.e.a surface that exhibits no irregularities in the form of shoulders orprojections.

Attachment segment 34 has in the upper region a configuration in theform of a sleeve 43 having an axially continuous opening 44 throughwhich optical shaft 28 is passed. In the distal region of attachmentsegment 34, a segment 46 of opening 44 is configured in accordance withthe outer contour of shaft 12, so that shaft 12 can be inserted into thedistal end of attachment segment 34 of handle 16.

Shaft 12 and handle 16 are joined to one another in lossproof fashion byway of screws 47 that pass through attachment segment 34 and shaft 12and do not project toward outer side 40. Sleeve 43 of attachment segment34 fits around shaft 12 with a thin material thickness on outer side 18facing away from handle 16, so that attachment segment 34 substantiallydoes not project beyond shaft 12 on outer side 18. The aforesaidmaterial thickness has precisely the dimension necessary for secureattachment of handle 16 to shaft 12.

Handle 16, or more precisely handle segment 36 of handle 16, protrudesobliquely toward the distal end from shaft 12 so that a longitudinalcenter axis 48 of handle 16 forms an angle of approximately 45° with alongitudinal center axis 20 of instrument 10 when viewed toward thedistal end.

As is further evident from FIG. 2, shaft 12 is configured as acircumferentially close hollow shaft having optical shaft 28 ofendoscopic optical system 22 received in its interior.

An outer side 49 of shaft 12 facing toward handle 16, which liesopposite outer side 18, is convexly curved in cross section when viewedtoward longitudinal center axis 20.

Because of this convex curvature of outer side 49, and also because ofthe slight concave curvature of outer side 18, optical shaft 28 isreceived in shaft 12 centeredly with respect to longitudinal center axis20.

Overall, shaft 12 is configured in cross section as a flat oval or avery slight kidney shape.

Also present in shaft 12, on both sides of optical shaft 28, is anaxially continuous open space for the introduction of auxiliaryinstruments that are used to remove the great saphenous vein, forexample dissectors, grasping forceps, or the like.

Endoscope shaft 28 extends distally as far as spatula tip 14. Spatulatip 14 has a spoon-shaped curvature that opens toward outer side 18 ofshaft 12. Spatula tip 14 also tapers toward the distal end. A lateralwidening 50 is configured such that spatula tip 14 extends slightlybeyond shaft 12 toward outer side 18.

For quick-release attachment and locking of endoscopic optical system 22to attachment segment 34 of handle 16, two axially projecting pins 52,which can be brought into engagement with corresponding cutouts inattachment segment 34 of handle 16 and locked, are provided on eyepiecehousing 24.

A method for removing the saphenous vein in which instrument 10 is usedwill now be described with reference to FIG. 4.

FIG. 4 schematically shows the left leg 60 of a patient. Great saphenousvein 62, which is indicated in FIG. 4 with dashed lines, extendssubcutaneously from ankle region 64 through lower leg 66, past knee 68,and through thigh 70 into groin 72. Saphenous vein 62 runs along theinner side of leg 60.

The removal method described hereinafter makes it possible to removesaphenous vein 62 through two incisions 74 and 76, and in fact inprinciple through only one of incisions 74 or 76.

After anesthetization, the patient is positioned supine on the operatingtable, leg 70 being rotated slightly outward.

If great saphenous vein 62 is to be removed principally from thigh 70and only partially from lower leg 66, only incision 74 is necessary;this is made with a scalpel, as a transverse incision, slightly aboveknee 68. If great saphenous vein 62 is to be removed principally fromlower leg 66 and only partially from thigh 70, only incision 76 isnecessary; this is made as a transverse incision slightly below knee 68.

If the entire saphenous vein 62, from ankle region 64 to groin 72, is tobe removed, it is more favorable if both incisions 74 and 76 are made.

“Transverse incision” is understood to mean that the cuts are madetransverse to the longitudinal direction of thigh 70 or the longitudinaldirection of lower leg 66. The length of the incisions is approximately2 to 3 cm.

As is evident from FIG. 4, incisions 74 and 76 are located in theimmediate vicinity of saphenous vein 62.

Incision 74 and/or 76 is first opened up down to the saphenous vein 62.

Instrument 10 in FIGS. 1 through 3 is then fitted with endoscopicoptical system 22. A video camera, connected to a monitor on which theendoscopic image is observed, is connected via an adapter to eyepiececup 26.

Mobilization of saphenous vein 62 in the thigh then begins, the firststep being created, using instrument 10 in FIGS. 1 through 3, asubcutaneous channel or cavity along the great saphenous vein.

This is done by inserting instrument 10, with spatula tip 14, intoincision 74. Outer side 18 of shaft 12 facing away from handle 16thereby rests against knee 68, and spatula tip 14 points toward groin72.

Instrument 10 is then slowly and carefully advanced, under endoscopicvisual supervision on the monitor, along saphenous vein 62 toward groin72.

Spatula tip 14 thereby creates a subcutaneous channel or cavity alongsaphenous vein 62. As spatula tip 14 is advanced, endoscopic visualsupervision is used to ensure that no undesired additional subcutaneouschannels are created.

In order to make way for side branches of saphenous vein 62 asinstrument 10 is advanced, instrument 10 is correspondingly rotatedslightly as it is advanced along saphenous vein 62.

If saphenous vein 62 is to be removed all the way to groin 72,instrument 10 is advanced along vein 62 until spatula tip 14 has reachedgroin 72; otherwise it is kept at the intended removal endpoint.

A subcutaneous channel has now been created along saphenous vein 62, andsaphenous vein 62 will subsequently be detached from its side branches.

For this purpose, while instrument 10 remains inserted, additionalinstruments such as scissors are introduced into incision 74 in order tocut saphenous vein 62 off from its side branches.

Before the side branches are cut through, they are clamped in situ witha clamp applicator (not shown) in order to interrupt the blood flow.

High-frequency current-assisted instruments, such as bipolar ormonopolar scissors, are particularly suitable for cutting, sincebleeding can be avoided to the greatest possible extent when suchinstruments are used. This is because the stubs of the side branches canbe simultaneously coagulated by the action of the high-frequencycurrent.

Once saphenous vein 62 in thigh 70 has been detached from its sidebranches, instrument 10 is kept inserted and a vein dissector 78, shownin FIGS. 5 and 6, is introduced; its distal end has an eye curvedtransversely to the longitudinal direction of the instrument inapproximately the shape of a semicircle or three-quarter circle.

After insertion through incision 74, eye 80 is placed around saphenousvein 62 to groin 72, thereby scraping away from great saphenous vein 62any subcutaneous tissue that is still adhering.

Saphenous vein 62 is now completely mobilized, but has not yet been cutthrough at its end in groin 72.

All the aforesaid actions, i.e. detaching great saphenous vein 62 fromits side branches and detaching great saphenous vein 62 from theattached subcutaneous tissue, take place with continuous visualsupervision on the monitor via endoscopic optical system 22 ofinstrument 10, which remains in place in the operative area during theseactions. In this context, instrument 10 is in each case positioned, bybeing advanced or pulled back, so that spatula tip 14 is located atthose particular points at which dissection is currently beingperformed.

The spoon-like widened configuration of spatula tip 14, in particularwidening 50, forms in each case a cavity in which it is then possible towork in a correspondingly safe manner, as described above, with theapplicator, the respective cutting instrument, or the dissector.

Following complete mobilization of great saphenous vein 62 in the thigh,instrument 10 is taken out of incision 74 and introduced once again intoincision 74 but with spatula tip 14 pointing toward ankle region 64,after which the same actions described above are performed to mobilizesaphenous vein 62 in the lower leg.

If removal is to occur all the way to ankle region 64, incision 76 isbetter suited for this purpose.

Following complete mobilization of saphenous vein 62 in lower leg 66,saphenous vein 62 is temporarily pulled slightly out of incision 76 or74. A suture is placed around the pulled-out portion and tied into aloop that can be tightened.

The loop, not yet tightened, is then slid along great saphenous vein 64to ankle region 64 using vein dissector 78, under endoscopic supervisionvia instrument 10.

At ankle 64, the loop is then tightened in order to tie off greatsaphenous vein 62 at ankle region 64.

Saphenous vein 62 is then cut through with a scissors in front of loop(as viewed from knee 68). The detached lower-leg segment of saphenousvein 62 can then be pulled out through incision 74 or 76.

The same procedure described above is then performed in thigh 70 inorder to tie off saphenous vein 62 in the region of groin 72 anddetached it at a point in front. Saphenous vein 62 is now completelydetached and is pulled completely out of leg 60 through incision 76 or74.

Saphenous vein 62 removed in this fashion is then available for a bypassoperation.

Saphenous vein 62 can be appropriately stored in a solution until it isused in the bypass operation.

Incision 74 and/or incision 76 are then appropriately sutured, and leg60 is wrapped in an elastic bandage for twenty-four hours.

What is claimed is:
 1. A medical instrument for endoscopic removal ofthe saphenous vein, comprising: an elongated shaft; a spatula tip at adistal end of said shaft; a handle disposed in a proximal region of saidshaft and affixed thereto, said handle projecting laterally from saidshaft; and an endoscopic optical system comprising an eyepiece cuparranged at a proximal end of said instrument, wherein said handle isjoined to said shaft in such a way that an outer side of said instrumentfacing away from said handle has a continuous straight surface that,from the distal to the proximal end, is free of projections; saideyepiece cup is arranged on an eyepiece housing of said endoscopicoptical system which has an outer side, facing away from said eyepiececup, that approximately aligns with said outer side of said instrumentfacing away from said handle; a longitudinal center axis of saideyepiece cup is inclined with respect to a longitudinal center axis ofsaid shaft at an angle of less than 90°; a longitudinal center axis ofsaid handle and said longitudinal center axis of said shaft define afirst plane; said longitudinal center axis of said eyepiece cup and saidlongitudinal center axis of said shaft define a second plane; and saidfirst plane is inclined with respect to said second plane at an angle ofless than 90° in either a clockwise or counterclockwise direction. 2.The instrument of claim 1, wherein said handle has an attachment segmentthat is configured in its upper region in the form of a sleeve whichfits over an axial portion of said shaft with the least possiblematerial thickness on said outer side of said shaft facing away fromsaid handle.
 3. The instrument of claim 1, wherein said longitudinalcenter axis of said eyepiece cup forms an angle in the range from 30° to60°, preferably 45°, with said longitudinal center axis of said shaft.4. The instrument of claim 1, wherein said shaft is configured as acircumferentially closed hollow shaft for reception of an optical shaft,extending to said spatula tip, of said endoscopic optical system.
 5. Theinstrument of claim 1, wherein said outer side of said shaft facing awayfrom said handle is configured with a slight concave curvature in crosssection when viewed toward said longitudinal center axis of said shaft.6. The instrument of claim 1, wherein said outer side of said shaftfacing away from said handle is convexly curved in cross section whenviewed toward said longitudinal center axis of said shaft.
 7. Theinstrument of claim 1, wherein said spatula tip has a spoon-shapedcurvature that opens toward said outer side of said instrument facingaway from said handle.
 8. The instrument of claim 1, wherein saidspatula tip has a lateral widening so that it extends beyond said shaft,at least on one side, transversely to its longitudinal center axis. 9.The instrument of claim 1, wherein said spatula tip tapers toward itdistal end.
 10. The instrument of claim 1, wherein said handle projectsfrom said shaft obliquely toward said distal end of said shaft.
 11. Theinstrument of claim 1, wherein said angle at which said first plane isinclined with respect to said second plane is less than 10°.
 12. Theinstrument of claim 11, wherein said angle at which said first plane isinclined with respect to said second plane is 0°.
 13. A method forendoscopic removal of the saphenous vein from a patient's leg, includingthe steps: providing an instrument, comprising: an elongated shaft; aspatula tip at a distal end of said shaft; a handle disposed in aproximal region of said shaft and affixed thereto, said handleprojecting laterally from said shaft; and an endoscopic optical systemcomprising an eyepiece cup arranged at a proximal end of saidinstrument; wherein said handle is joined to said shaft in such a waythat an outer side of said instrument facing away from said handle has acontinuous straight surface that, from the distal to the proximal end,is free of projections; said eyepiece cup is arranged on an eyepiecehousing of said endoscopic optical system which has an outer side,facing away from said eyepiece cup, that approximately aligns with saidouter side of said instrument facing away from said handle; alongitudinal center axis of said eyepiece cup is inclined with respectto a longitudinal center axis of said shaft at an angle of less than90°; a longitudinal center axis of said handle and said longitudinalcenter axis of said shaft define a first plane; said longitudinal centeraxis of said eyepiece cup and said longitudinal center axis of saidshaft define a second plane; and said first plane is inclined withrespect to said second plane at an angle of less than 90° in either aclockwise or counterclockwise direction, making an incision near thesaphenous vein in the patient's leg; and introducing said instrumentinto said incision and advancing said instrument under visualsupervision though said endoscopic optical system along said veinthereby creating a subcutaneous channel along said saphenous vein. 14.The method of claim 13, wherein after creating said subcutaneous channelside branches of said vein are detached by means of at least one cuttinginstrument, which is introduced into said shaft of said instrument whilekept inserted in the patients leg.
 15. The method of claim 14, whereinafter detaching said side branches a vein dissector having an eye curvedtransversely to a longitudinal direction of said vein dissector isintroduced into said incision, said eye is placed around said saphenousvein and advanced along said vein thereby scraping away subcutaneoustissue adhering at the saphenous vein, said advancing of said veindissector taking place under visual supervision through said endoscopicoptical system of said instrument while kept inserted in the patientsleg.
 16. The instrument of claim 13, wherein said angle at which saidfirst plane is inclined with respect to said second plane is less than10°.
 17. The instrument of claim 16, wherein said angle at which saidfirst plane is inclined with respect to said second plane is 0°.